Our broad objective is to improve understanding of the mechanism underlying pattern recognition, learning and perception by studying the mammalian visual pathway. A major emphasis will be placed on the study of the development of these mechanisms and their modification by early experience. The principal technique will be that of classical single neuron physiology. This tool will be used to assay the effects, including time course, of a variety of environmental manipulations. In addition, single neuron receptive field studies will be used to investigate the role of neurotransmitters, particularly the inhibitory ones, in the visual system's organization and development. We will also carry out a morphological and biochemical analysis of the preparations, closely correlated with the physiological studies.